London: Be positive! You will be well very soon. This common advice may neither help you get through illness nor make you better quicker, say researchers.

A new study of cancer patients in Finland and Sweden, published in the 'American Journal of Epidemiology', found no association between survival rates and whether people were positive or negative in their outlook.

The study looked at 4,600 people with cancer over 30 years, and found that whether they were extrovert or neurotic, their attitude to life had no relationship with how long they survived their illness.

It's not an isolated finding.

An analysis of research by Dr James Coyne at University of Pennsylvania School of Medicine, found that there were no good quality studies showing that "positive psychology" had any effect on physical health.

In one of his own large studies, he found that the sense of emotional wellbeing of cancer patients had no effect on how long they lived.

Even British researchers and health staff are becoming concerned that American lifestyle gurus who urge people to "be positive and live longer" may be doing more harm than good as reported.

Claire Murrell, head of nursing at the Barts and the London Hospital Cancer Unit, is concerned that too many people are being urged to "be positive" after cancer diagnosis, when they need to realise that they will experience emotional lows.

"I think that some people with cancer do come down with a bump when they realise that, for their entire positive attitude, they haven't been cured. I've come across people who feel lot of pressure to be positive, sometimes from family and friends, at a time when they really don't want to," she said. There are also some studies suggesting that people who are born with, or develop early in life, an ability to dwell on what can be done, rather than what can't, may be healthier.

Research on 1,000 people attending the famous Mayo Clinic in the US over 30 years found that those classified as optimists had a 19 per cent higher chance of still being alive than pessimists.

But this is all different from saying that taking a positive attitude makes you healthier.

Dr Gerard Molloy, chair of the UK Society for Behavioral Medicine's scientific committee, says that though psychological traits such as optimism may be linked to longer survival from illness, there is no evidence that such traits can be cultivated by "positive thinking".

"Some of the strongest evidence revolves around personality types. But personality type is, by definition, impossible to change. I think the idea of adopting a positive psychology has come over from the US, where there's a 'Yes we can' culture and the wellness thing is hanging on to the coat-tails of that," Molly said.